These were Barca's last six visits to Czech Republic

The fact Barca have never faced Slavia Prague does not mean they have never been to Prague. That is wheere Johan Cruyff talked about the 'environmnet' back in 1992. 

In fact, they have been to Prague frequently although in 2012, they went to Pilsen. That was the last time Barca went to Czech Republic. Pep Guardiola's men won 0-4 versus Viktoria Plzen and Messi scored three goals. His 200th, 201st and 202nd of his career. 

Beforehand, Barcelona faced Sparta Prague, Dukla Prague and Spartak Hradec Kravole. Kralove were knocked out at the quarter final stage of the old European Cup after losing the first game 4-0 and drawing the second 1-1. 

Against Dukla, after 21 years, Barcelona lost 1-0 away from home, thanks to a goal from Jan Kozak. Barcelona ended up winning the European Cup Winners Cup that year. 

The other three Barca visits were at Sparta Prague: 1-2 in 85/86, 1-0 in 91/92 (with Cruyff criticising the 'environment') and 1-2 in 99/00. All of these results were in the European Cup/ Champions League and in the early rounds or group phase. 

In short, Barca have won three, drawn once and lost twice in Czech Republic.